Please explain the >> in this program

Question

What is the extraction operator doing? I have never seen it used this way.

void DecimalToBinary(int decimal)
{
int remainder;

if(decimal <= 1)
    {
    cout << decimal;
    return;
}

remainder = decimal % 2;

/*----->>>*/ DecimalToBinary(decimal >> 1);/*what is the extraction operator doing?*/
cout << remainder;
 }

It's a right shift, not an extraction. http://publib.boulder.ibm.com/infocenter/lnxpcomp/v8v101/index.jsp?topic=%2Fcom.ibm.xlcpp8l.doc%2Flanguage%2Fref%2Fbitshe.htm — Joe, Feb 25 '13 at 00:08
There are lots of things about C++ that suck, and "operator overloading" is arguably one of them. The original meaning of operator ">>", from C, is "binary right shift": [Absolute Beginners Guide to Bit Shifting](http://stackoverflow.com/questions/141525/absolute-beginners-guide-to-bit-shifting) — , Feb 25 '13 at 00:10

score 3 · Answer 1 · answered Feb 25 '13 at 00:08

3

It was a bitshift operator long before it was an extraction operator.

answered Feb 25 '13 at 00:08

user229044

232,980
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score 3 · Accepted Answer · answered Feb 25 '13 at 00:09

It is not an extraction operator - it is a bitwise shift - or "divide by two" (although it may not work correctly for negative numbers).

The "extraction operator" is just borrowing one of the less common operators in the C language to do something completely different with it.

score 2 · Answer 3 · answered Feb 25 '13 at 00:09

2

This is the bitshift operator, in this case it shifts the whole value to the right by one bit.

E.g.:

 13 >> 2

 01101 
 00110 //right by one
 00011 //repeat

 = 3

answered Feb 25 '13 at 00:09

Adam Schmidt

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Please explain the >> in this program

3 Answers3